Question

A 25 newton force applied on an object moves it 50 meters. The angle between the force and displacement is 40.0°. What is the value of work being done on the object?
0 joules
9.6 × 10^2 joules
1.2 × 10^3 joules
-9.6 × 10^2 joules
-1.2 × 10^3 joules

Answer 1

Work is defined as:
$W = \int\limits {\overrightarrow F \cdot} \, \overrightarrow {ds} = \int\limits {F cos \theta} \, ds$

where F is the applied force, ds is the incremental displacement and θ is the angle between the force and the displacement.

If the force F is constant the equation simplifies to:
$W = (Fs) cos\theta$

In your example:
$W = (25N)(50m)(cos 40 \textdegree) = 957,6 J = 9.6 \times 10^2J$